Indicator



L. E. DQDGE 2,200,917

INDICATOR Filed June 27, 1936 3 Sheets-Sheet 2 INVENTOR May 149 14949 L. E. DODGE 2,200,917

` INDICATOR Filed June 27, 1936 3 Sheets-Sheet 3 l Ul! C3 Q 105 U 106 P n LII F20 "H P 1% P4 M M" A, E. W 11@ M5 MB M4 M@ 151 )55 @QAMGM/ MyX Patented May 14, 1940 UNITED STATES INDICATOR Lyman E. Dodge,

Morris Township,

Morris County, N. J., assignor `to Frank C. La Mar,

Tucson, Ariz.

Application June 27,

4 Claims.

This invention relates to electrical fuse devices, especially to integrity indicator means for cartridge type fuses, and more particularly to the class of such integrity indicators in which the 5 indicator device is formed as a unitary structure having an entity distinct from that of the cartridge fuse or other type of fuse with Which the indicator device is intended to be assembled in use.

An outstanding object of the' present invention is to provide a means by which it is possible to have the integrity indicator so conjoined with the fuse cartridge supporting structure, when in use, that the indicator will not be displaced by the vibrations and shocks encountered ordinarily in the use of such protective devices, also to provide that the integrity indicator shall be so disposed with relation to the fuse cartridge that its presence will not interfere at all with manipulation 20 of the fuse cartridge during inspections, adjustments and renewals thereof, but that, on the contrary, the fuse cartridge, and the integrity indicator, shall each be capable of removal and replacement independently of the other. By this means the invention avoids the chance of mislaying the indicator, losing, or forgetting to put it back, and so leaving the fuse Without an integrity indicator.

Among other requirements Which are desirably to be satisfied by a fuse-integrity indicator intended for assembly with a cartridge type fuse, and to provide for which is the general object of the present invention, is the need that the indicator device shall be capable of assembly 35 readily with, and attachment to, the structure which serves to support the fuse cartridge, being provided with electrical terminals by which the fuse is contacted and thereby included in the Working circuit to be protected; also that such an integrity indicator shall be adaptable for use with cartridge fuses of generally standard sizes and types, though differing in non-essential details; also that the adaptation of the indicator to a given type of fuse can be effected Without alteration in the structure of the fuse cartridge by a user, and that if any alteration of the fuse cartridge, or of the integrity indicator, must be made by the manufacturer, in adapting the indicator to one or another make of fuse cartridge, such alteration shall be of an inconsiderable character, and may be performed at the manufactory instead of at the place of installation of the carplied to cartridge fuse assemblies for the afore- 1936, Serial No. 87,643

said purpose, fail to satisfy the foregoing requirements in many respects, and none of such indicators are to be regarded as meeting all of the requirements in a completely satisfactory manner.

Among the outstanding deciencies that have been characteristic of some of the fuse-integrityindicators novv on the market, may be mentioned the tendency to shake away from the cartridge and fall into positions wherethey cause shorts, or crosses, in the electrical Working circuit sought to be protected by the fuse, and the integrity or condition of which is desirably to be indicated reliably at all times; also the tendency to become loose to such an extent that the electrical contact is impaired, or broken, even if the indicator is apparently in place and operatively connected; a defect which is particularly dangerous for the reason that a defective circuit condition may exist without being signalled, the normal appearance of the indicator being deceptive.

Other objects and advantages will appear as the description of the particular physical embodiment selected to illustrate the invention progresses, and the novel features will be particularly pointed out in the appended claims.

In describing the .invention in detail and the particular physical embodiment selected to illustrate the invention, reference Will be had to the accompanying drawings and the several views thereon, in which like characters of reference designate like parts throughout the several views, and in which:

Figure l is a View in side elevation, partly in section, or a protective device for electrical circuits, in which a fuse cartridge element is shown in assembly with a support and with an integrity indicator element, the supporting structure and associated connections being shown partly in section; Fig. 2 is a view in end elevation of the assembly illustrated in Fig. l; Fig. 3 is a fragmentary detail View in plan of certain parts shown in Fig. l, with the cover of the indicator removed; Fig. 4 is a horizontal sectional View similar to Fig. 3 but with the indicator lamp omitted, to reveal the support therefor; Fig. 5 is a detail view in perspective of the supporting bracket for the indicator element shown in Fig. 1, but the bracket being shown separately; Fig. 6 is a similar perspective view in detail of another bracket shown Iat the right hand of Fig. l, the bracket being taken separately; Fig. 7 is a vieW in side elevation similar to Fig. 1, but illustrating a modiiication; Fig. 8 is a fragmentary detail view of the supporting base shown in Fig. '7, but with a modied disposition oi the conductor which completes the indicator shunt; 9 is a fragmentary detail view in side elevation, partly in section, of another modiiication of the integrity indicator element and its associated parts; Fig. l0 is a fragmentary, detail view in end elevation, partly in section, of still another modication of integrity indicator and associated parts; Fig. l1 is a view in plan oi the parts as shown in Fig. 10; Fig. l2 is a detail view in perspective, on a greatly enlarged scale, oi the indicator-lampbracket and a resistance element, associated in a unitary structure separately from the base of the protective device; Fig. I3 is a fragmentary, detail view of the indicator lamp as in Fig. l0, but illustrating a protector shield for the lamp, the View being taken on a larger scale; Fig. le is a View in horizontal section on the line la-ill of Fig. 13; Fig. l5 is a view in perspective of a modied form oi shield; Fig. i6 is a view in horizontal section, taken on the line iiii@ of Fig. l5; 17 is a view in side elevation illustrating an assembly of a modied form of integrity indicator element ivithacartridge fuse element, mounted on a supporting base of which a part only is shown, in section; Fig. 18 is a View in end elevation of the structure shown in Fig. 17; Fig. 19 is a plan View of the structure as shown in Figs. l? and 18; Fig. 2G is a View in side elevation oi another niodied form of integrity indicator element in assembly with a fuse cartridge element mounted upon a supporting base; Fig. 21 is a plan view of the structure shown in Fig. 20, showing in horizontal longitudinal section an adjustable shuntconnection forming part of the structure; Fig. 22 is a fragmentary detail view ol a modified form of adjustable electrical shunt connector including an integrity indicator element adapted to be assembled a fuse cartridge element; Fig. 23 is a view in end elevation of another modified forni of integrity indicator element and supporting means therefor, in assembly with a fuse cartridge element; Fig. 24 is a view in side elevation of still another modified form of integrity indicator with a swinging support, and shown in assembly with a terminal of the electrical circuit to be protected; Fig. 25 is a view in rear elevation of the structure shown in Fig. 24.

In a now-preferred embodiment of the invention selected for illustration and description, referring first to the structure shown in Figs. l to 5, inclusive, the part designated by the reference character F is a fuse cartridge of the conventional ferrule type, mounted in clips CC made of sheet metal, and which embrace a ferrule Il] at one end of the use cartridge and e. ferrule ll at the other end thereof, the ferrules constituting the end terminals of a fusible element l2 confined Within a barrel i3 of insulating material.

The feet iii of the clips are secured to the base B by screws i8 which transiix also metal straps il extending outwardly toward each end, Where binding screws 2l and 22 are provided to serve as terminals by which the fuse cartridge element may be included in series in the electrical working circuit to be protected.

Each binding screw 2l, 22 serves to hold down also the foot, as 59, 2S, oi one of a pair of brackets B and B, there being one bracket adjacent each end of the fuse cartridge, and each so disposed as to cause no interference by the brackets with ready removal of the fuse cartridge F, at will, independently of the indicator element.

The bracket B', in further pursuance of the invention, serves as a support for the integrity indicator element, designated generally by the reference character I, and which comprises, in the instance illustrated in Figs. l to 3, a lamp N of the neon-lled discharge type, enclosed in a casing 23, the lamp being visible through an orifice 2li (see Fig. 2).

As shown in Fig. 3, in which the cover oi casing 23 is omitted, the lamp is provided with the usual terminals .'5 and 2G oi which the rst-named is connected to one end or" a resistance R, preferably of the order of 50,060 ohms to 100,000 ohms, from the other end of which a conductor 2'! runs, through an orifice 28 in the bottom or" the casing to a terminal stud 3i extending from the base of casing 23 and adapted to enter a complemental keyhole slot 29 in a bracket lug best seen in Figs. 4 and 5, ano her keyhole slot 30 therein serving to cooperate with a stud il?. also provided at the base of the casing 23. as shown in Fig.l2.

When thus mounted, the indicator element I is securely held, entirely out of the way of the fuse indicator element F, and each of said elements may be removed while the other remains in or each may be tested, inspected and adjusted Without disturbing the other.

In the structure shown in Figs. l and 3, one terminal, as 26, of the indicator means, the indicator being in this instance the neon discharge lamp N, is extended by an insulated conductor portion 25 to be connected with the bracket B at the other end or the fuse cartridge element F, for the purpose of completing the shunt around the element F as already described.

As shown in Fig. 6, the bracket B has a foot 2li with an open slot 2B and lugs 39 to aid in main taining alignment of the foot upon the underlying strap Il. It has also an upright post 20.1: with a bracket part 23x bent over in parallelism with the foot and having an eye 3b adapted to receive the bared end 25:12 of conductor 2B illustrated in Fig. l. The latter is wedged iirmly in a slit 3D but may be detached readily therefrom when it is desired to remove the fuse cartridge F or the integrity indictor I. When the .removal of the indicator is not necessary, the conductor is simply drawn out of the slot 3D, and from the eye 3B', and remains connected with the indicator, the latter retaining its established position on the other bracket B.

In the modification illustrated in Fig. 7. the

an electrical connection with an eye or eyes 3U" formed on the spring clip member C". The conductor 26 is led down through orices 34 and 35 formed in the upper and lower bends (see Fig. 5) which join the post of the bracket B to the foot I9 thereof, and to the bracket part 33 thereof.

An open slot 4D permits the foot I9 to be slipped` under the binding terminal screw 2 l, which transxes the underlying strap l'l by which current is led to fuse clip C'. the foot I6 of the clip being transiixed by the screw I8, which secures the ioot and strap to the base.

In the modification illustrated in Fig. 8, the conductor 263 is led from the indicator element.

just as is the conductor 2li (shown in Fig. 7).

down through orices 34 and 35 and through an orice 43 which is formed in the base B near the foot I9. In the lower face of the base, a channel 1M is provided, leading past the head i3 of screw I8, to the recess 46 which receives the head I8 of the screw I8 which secures the strap IT" (see Fig. 7) to the base, and the conductor 263 is thereby so disposed as to complete the shunt circuit for the lamp N, around the fuse.

It will be understood of course that the recess containing the head I8' of the screw I8 is sufficiently deep to enable the insulated conductor 263 to clear the screw-head I8', and it is also clear that in this instance, where the shunt conductor is led below the base, as well as in the instance shown in Fig. 7 where the conductor is led through the cavity l'lrc, the removal of the fuse cartridge may be accomplished without disturbing the integrity indicator and its connections, so that these illustrative examples of physical embodiments of the present invention have in common the desirable provision for maintaining the integrity indicator in its established position at all times (except when it must be itself replaced), and there is accordingly no danger that it will be lost, misplaced or forgotten, when the fuse cartridge is removed, an operation which occurs naturally more frequently than a similar replacement of the integrity indicator structure.

It is also to be noted that when the indicator means I is removed, for any reason, it is not necessary to remove the bracket B', and its connections with the terminal strap I7 can be maintained as originally established, a notable advantage, as it assures the continuance of good electrical connections at that point in the circuit. The provision of an orice 41 in the bracket part 33 makes it possible to reach the head 2l of the binding screw readily with a screw driver, so that the screw can be tightened, or loosened, whenever necessary after removal of the indicator means I.

Inasmuch as the axis of movement of the indicating means I, when being removed by shifting the studs 33 toward the larger orices of the keyholes 29 and 3U (see Fig. 4) is at right angles to the general trend of the! insulated conductor 26' or 26" or 263, as the case may be, it is possible to free the indicating means from its bracket in each of the forms above described, without disconnecting the conductor at its end remote from thelamp, and as the conductor is preferably an integral extension of the lamp terminal, or permanently connected therewith by some form of metallic union, the easily attachable-detachable connection of the indicator means to its bracket does not interpose any diiculty in the way of its removal for any purpose, including that of gaining access to the binding screw 2l.

In Fig. 9, a modication is shown in which the above desirable capacity for easily attachabledetachable assembly of the indicator means I is provided, with a somewhat dierent disposition of the bracket part upon which the indicator device I is mounted, this part having the same form of complemental studs 33 and keyhole slots 29 and 30 shown in the preceding gures and described with reference thereto. The variation consists in arranging the keyhole slots so that, as indicated in Fig. 9, the studs 33 are disposed in a lin-e parallel with the length cf the cartridge fuse F9. Thus, the indicator means I will be shifted manually along that line, for purposes of attachment and detachment, relatively to the bracket part 50 of bracket B9 and the insulated conductor 263 serves the same purpose, and is similarly disposed to complete the shunt around the cartridge fuse FJ so that it will not be necessary to repeat that part of the description covering this feature.

This disposition of the bracket part 50, with its stud and keyhole slot connection arranged coaxially of the protective device, may of course be utilized with various forms of cartridge fuse, indicator means, fuse-cartridge and supporting structure. tridge F9 is of the known knife-blade type, havign at each end a tang like that shown at T projecting'beyond a metal cap 5l screwed on a ferrule 52, and connected with the fusible element l2 conned within the barrel Il of the cartridge.

Each end tang T is held in clips 53 of known form,fand the bracket B9 consists of an angle piece of sheet metal having an attachment part 54, with a slot (not shown) enabling the slotted part 54 to fit upon the tang T and be embraced between the clips 53 and the screw cap 5I, making therewith a good electrical connection which is enhanced by the rubbing action of the contiguous edge of the cap if the latter happens to become loose.

The bracket part 50 has already been described, but it is to be noted that in the event that it is desired to remove the fuse cartridge F9, it is possible to shift the indicator means I readily in an inward direction and then to tilt it out of the keyholes in bracket part 50, leaving the indicating lamp with its casing 55 still attached by conductor 26,3 to the binding screw 56, so that when desired the indicator I can be restored by simply reversing the direction of shifting just described, no binding screw connections having been impaired.

The bracket B9 Will accompany the fuse cartridge F9 when the latter is removed from clips 53, and may be slipped off the tang T in order to clear the cap 5| for the unscrewing operation necessary to permit withdrawal and replacement of the fusible element I2.

This form of device has the advantage under certain conditions that the indicator element as such is readily detachable from the removable fuse cartridge, but need not be wholly disconnected from the circuit.

In Figs. 10 to 12 is shown a modification of the invention, which illustrates an integrity indicator element 110 of very compact construction, comprising a suitable indicator lamp N' such as a neon-lled discharge lamp, having a threaded metal sleeve 59 connected in known fashion with an interior terminal of the lamp and screwed into a metal socket 60 forming part of a bracket which is best shown in Fig. 12, being there designated generally by the reference character B12. 6B electrically with one end of a suitable resistance R spaced from the socket by cup-shaped insulation 62, the other end of the resistance being in electrical connection, as at 54, with a bracket part extending laterally from a post 61 which is bent up from a foot 65 of the bracket the foot being suitably slotted, as at 11 to be tted under a binding Screw 68 (see Figs. 10 and 11) which serves as an end terminal by which the fuse cartridge element Flo may be included in the electrical circuit to be protected. The cartridge shown is, for illustrative purposes merely, of the ferrule type, having an end member 'lu embraced by spring clips 1l extending upward from the foot 69.

There is a similar clip and binding screw at the other end of the fuse cartridge structure (not shown) and in order to complete the shunt in which the indicator means is included, relatively to the fuse cartridge F10 Whose condi- In the present instance the fuse car- A strap 6I connects the lamp socket tion is to be indicated therebypa conductor 12 is provided, one bare .end of which may desirably be riveted as at 13, into the insulating cup 62 in position to be contacted by the usual central base stud at the bottom of lamp N', and this contact is accordingly insulated in known manner from the metal lamp socket G0. The insulated conductor 'l2 is extended to, and connected with, the binding screw or some electrically associated part at the other end of the fuse supporting structure (not shown).

By reference to Fig. 1l, it will be seen that when the foot 6G of the bracket B12 is slipped under the binding screw 68, the upright bracket post 6l is disposed at the side of the cavity 'i4 in the end l5 of the base B, having the binding screw 6B free for access at all times.

The fuse cartridge element F10 can be removed independently of the entire integrity indicator element 116 at any time, and the indicator element can be applied, as an entity, to existing fuse cartridge assemblies and can be removed therefrom, without essential alteration of the structure. The indicating means, in this instance the lamp can be unscrewed from its socket and replaced by a fresh lamp, without the use of tools, and without disturbance of any other electrical connection.

The whole integrity indicator element occupies a space at the end of the fuse cartridge assembly which is ordinarily waste space, and the upstanding character of the indicator lamp constitutes it a very visible and attention-arresting means to signal the circuit condition, when energized by flow therethrough of an adequate current in the shunt, upon fusion of the fusible element in the fuse cartridge F10, in known manner.

Under certain conditions, it may be desirable to provide protection for this lamp against mechanical contacts apt to be encountered in particular installations, and for this purpose the drawings illustrate diierent illustrative forms of shields.

That shown in Fig. i3 at 89 may be brieiiy designated as a pulpit-type shield, having a ringshaped base 8i which surrounds the lamp socket 82 and resistance R, these latter parts corresponding' preferably to those described with reference to Figs. lo to l2 and which are shown in detail in Fig'. 12.

In Figs. l5 and 16, a shield B5 is shown, of a type which is designed to fit over the lamp N without extending downward over the socket upon which the shield is seated. This shield has a waist 8G sufficiently constricted to afford an easy grip for the digits of an operator-s hand in manipulation of the shield, an orice 8l being provided in the waist at each side thereof, amil another orifice 88 in the end, through all of which orifices the light of the lamp will escape when it is energized, in the manner already described. i

in the modification of the invention illustrated in lT'igs. 1'?, 18 and 19, 'the part designated by the reference character F1rl is a cartridge fuse element of known type, having a barrel i l enclosing fusible element (not shown) in electrical connection with metal end caps or terminals I3 and lil by which the cartridge fuse is held in a pair of spaced clips C' and C, the feet I5 (see Fig. i8) of which are secured to base B16 by suitable means, such as the screw I8 indicated by dotted lines. Beyond the clips C and C" respectively, similar` clips C3 and C*1 are provided,

in electrical connection with the iirst named pair Aof clips and preferably integrally formed therewith out of sheet metal, a pair of clips C3, of the knife blade type, preferably being provided in conjunction with the clip C and another pair C1 in conjunction with the clip C, these knife blade clips being disposed near the base B16 at the ends of feet I, branching laterally from a tongue |88 over which extends a strap il' provided with a binding post P which serves as a terminal by which the assembly can be included in the electrical circuit to be protected, in known fashion.

The reference characters P and P indicate guides or clips for the conductors L and L" leading to the assembly from the two sides of the working circuit.

In pursuance of the invention, an integrity indicator element 116, comprising an elongated body of insulating material having therein a suitable indicating means N visible through an orifice Il, is mounted as a bridge member upon a pair of standards U and U of inverted U-shape in end elevation, and the feet itt, fihi of which are formed as vertically disposed blades adapted to t into the several clips C3 and C4 respectively, as indicated, there being a pair of blades 5F25 on the member U', to enter the pair of clips C3, and a pair of blades Uit to enter the clips C1.

The U-shaped members U' and U" accordingly constitute each a terminal for the indicator means, the terminals of which, within the elongated body I16, are soldered, or otherwise suitably connected, to the medial portion of each U-shaped member, in well-known fashion, not illustrated in detail.

it is clear from the above disclosure that the integrity indicator 116 will be included in shunt with the fuse cartridge F17 in the working electrical circuit when in operative position as shovm in Figs. 17-19, and it will be understood that suoli resistance for the indicator will be provided as only to permit passage of sulicient current to energize the indicating means and yield a signal through the orifice IB'! when the fusible element in the fuse cartridge F17 shall have been fused by the passage of a current of predetermined strength.

At any time, the integrity indicator E16 may be removed manually, having the fuse cartridge F11 in place, or both the indicator and the fuse cartridge element may be removed by a single manual operation.

While the clips C3 and C4 may be of any suitable structure, it is to be noted that clips of the form illustrated, and best seen in Fig. 19, are preferred, each comprising a structure in which the upright parts |04 are struck up out of body of the laterals l 88, this constituting a very sturdy clip structure.

Similarly it is preferred to form each terminal strap |10 with a forked inner end, as indicated at |03, so that it can be tucked under the nut of the binding post P, and removed therefrom, while the leads L', L" remain attached to the forked terminals.

In the modifica-tion shown in Fig. 20 and 2l, the fuse cartridge element F26 and the cooperating terminal clips C and C may dcsirably be of known form, each of the clips having a forked strap H0, like that already described with respect to Figs. 17-19 provided with a binding post P5 to facilitate rapid installation in the working circuit the latter being represented by leads L', L" from sources of different potential.

The integrity indicator for this assembly may Cil comprise a device I of the type indicated by that reference character in Figs. 1 to 5 and described with reference thereto. 'Ihe indicating means is provided with a stud terminal 33, as in the earlier described structure, adapted to cooperate with the walls of a keyhole complemental aperture (see Fig, 21) in the bracket part 50 of a bracket B20 bent from an upright post which has at its base a ioot |66, suitably apertured to be transxed by one of the binding posts P5 having a nut P4 which acts to hold in assembled relation the extension i'i (see Fig. 2l) from the clip C" of the fuse cartridge supporting structure, with the forked end of strap |11, and the said foot |66 of the bracket.

Upon loosening the nut P4, the bracket B20 can be removed at any time, leaving the fuse cartridge F20 in place, and similarly the fuse cartridge F20 can be removed independently of the integrity indicator.

As hereinbeiore described the stud 33 of the indicating means I is in electrical connection with one terminal of-the indicating lamp N', and the other terminal of the indicating lamp has an insulated extension conductor |96 which is led along the base B, at one side of the fuse cartridge, to a clip C5 formed upon a strap S5 with an orice through which extends the binding post P5 at that end of the cartridge fuse structure.

The indicating means, in this instance the lamp N', is thus included in a shunt around the fuse cartridge element F20 and operates in known manner to signal the fusion of the fusible element (not shown) in the fuse cartridge element F20.

In pursuance of an important object of the present invention, as thus embodied, means are provided to permit the shunt conductor |96 to be adjusted to compensate for Variations in the length of the fuse cartridge intended to be used at F20. For example, if a one-time type of cartridge fuse is used, as shown, the clips C and C" should be disposed at about the distance apart illustrated, and the conductor I 96 need be no longer than shown in Fig. 21. It is, however, made of considerably greater length, in accordance with this feature of the invention, and the excess, or reserve length is coiled as shown at |9631, ready to be extended if required. An instance of such desirable elongation would arise when a fuse cartridge is used of the type having as end terminals metal caps screwed upon nipples, to permit replacement of the conned fusible element when expended by fusion. Such fuses are somewhat longer than one-time fuses of like capacity, and of course one-time fuses of greater capacity are apt to be longer than those of relatively small capacity. Other reasons for variation in length are common, and the provision made as illustrated in Figs. 20 and 21 constitutes this assembly What may be termed an all-purpose protective assembly of the type described, Within limitations which will be readily understood by those skilled in the art.

An added feature of advantage in the structure shown in Figs. 20 and 21 is constituted by the telescoping protective tubular members M and M", the latter being snugly iitted to slide within the former, and each having smooth bores to pass the conductor |96 freely and afford ample storage space for the helical reserve |9632.

This type of adjustable shunt can of course be applied to cartridge fuses of the knife-blade type, with but little need for alteration.

As another form of adjustable shunt, the drawings illustrate in Fig. 22, a pair of links M3, M4, in the dotted portions ci which is provided a binding bolt M, to hold the links together and keep them from lengthwise displacement when adjusted in length to compensate for the variations permissible in the lengthV of any fuse cartridge which it may be desired to insert between the terminals T3 and T4.

The terminal T3 may be constituted by the foot |66 of a bracket such as that shown in Fig. 20 and described with reference thereto, this bracket being connected to one side of the indicator means I22, for example one terminal of a lamp. The other terminal of the lamp (not shown) has an extension conductor ||6 which may be connected electrically to the shank M5 of link M3 in any suitable manner, as by soldering; While the link M4 has a shank M6 with a bend at Mrl tted into a clip M8 of the eye-shaped terminal member T4.

The mode of operation of this form of the shunt adjuster will be readily understood from the description of the preceding features of the present disclosure.

In Fig. 23, is shown a modiiied type of integrity indicator element 123 in assembly with a fuse cartridge element F23 mounted in clipsy C23 carried by a base B23. In this form of embodiment of the present invention, the indicator 123 is mounted in a pair of spring arms A, oi which only one is shown, it being understood that these arms are spaced apart suitably to receive the ends, as E', of an elongated body forming` part of the indicator element, and upon which the indicating means is carried. The ends: E will preferably be of metal, and the arms A may be coiled to form clips Cx adapted to be constricted upon, and to form Vgood mechanical and electrical contact with, the metal end terminals E of the indicator element.

The arms A are suitably mounted on the base B23, as by flanges c on an integral extension c leadingfrom the clip C23, or by a strap connected thereto by the usual binding post P23. This is a very simple form of mount for the integrity indicator element and can be easily retracted manually to its dotted line position for the purpose of clearing the way for removal of the fuse cartridge F23, yWhile the integrity indicator is still retained in its mount.

The integrity indicator may also be removed independently of the fuse cartridge, and when the integrity indicator occupies its operative, fullline position to which it is biased by the arm A, it is well disposed for an attention-arresting dis play of its signal closelyidentied with the fuse cartridge F23, of whose integrity or expenditure it is to Witness visibly.

In Figs. 24 and 25 is illustrated a modication of what may be termed the swinging type of integrity indicator this modification comprising a hinged bracket part B6 hingedly mounted at i5@ on an upright post ISI, bent up from a sheet metal foot |56 which is suitably apertured to be held by a known form of binding post terminal P22, the latter serving in the usual manner as one terminal by which the indicating means carried by the bracket part B0, as for example a neon discharge lamp N visible through an orifice n in the casing n', may be included in shunt with a fuse cartridge element (not shown) in an electrical circuit to be protected.

It will be understood that an insulated ccnductor, as |52, leads from the other terminal of the indicating lamp, and that connection may Sil be made thereby to a terminal atA the other end of the fuse cartridge structure, to complete the shunt, in substantially the manner hereinbefore taught.

The hinged bracket part B5 has a range of I swinging movement limited'bystops 153 and |54,

the latter serving to denne the operative position of the indicator shown in full lines, when it is disposed adjacent to the end oi a fuse cartridge element, indicated by the circle F24 in schematic fashion, so that its signal, when given, will be identiiied with the adjacent fuse cartridge element, and when not energized its present will be an indication that the fuse element FM is intact.

A spring 55 serves to bias the bracket B6 to the operative full line position until it is swung back manually toward the dotted line position, and the spring tends to bias the indicator to the dotted line position as soon as the bracket swings past the dead center of the springs line of connection between hook |57 and eye 158.

The operator can thus release the indicator, after swinging it back, and it will still occupy the dotted position, swung back to clear the way for the operator to work on the connections associated with the binding post P24. Accordingly, the form of the invention just described is characterized by aiTo-rdng complete accessibility to all of the working parts of the protective assembly of an integrity indicator element, a fuse cartridge element, and the supporting base with its circuit connections.

The indicator need never be disconnected, except for the substitution of a fuse indicating means when one is expended, and in that event the studs 33 of the indicating means N are simply shifted out of the keyhole slots in bracket 5E) as hereinbefore described, and a 4fresh one substituted in the manner known to the art.

Any suitable type of magazine indicator element may be utilized by suitable adaptation oi the bracket 5B, in any form of the invention forming the subject of this disclosure.

Although I have particularly described one particular physical embodiment of my invention and explained the operation, construction and principle thereof, nevertheless I desire to have it understood that the form selected is merely illustrative, but does not exhaust the possible physical embodiments of the idea of means underlying my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

l. In an integrity indicator device for a cartridge fuse, the combination, with a cartridge fuse element and a support therefor having terminals by which said fuse may be included in the electrical circuit to be protected, of an integrity indicator element including an indicating means and means to support said indicating means fully exposed at or abovethe level of the cartridge fuse, in attention-arresting position and in electrical connection with said terminals, thereby to include said indicator means in a shunt with said fuse in the working circuit, said device being characterized by having said fuse cartridge element removable while said indicating means remains in place and further characterized by having said integrity indicator element supported by a support having a pair of bracket connectors one at each end of said cartridge fuse element and including binding screws, and each having a foot with an open slot by which said foot can be iitted to one of the binding screw terminals on said support, one of said brackets having bracket part with a keyhole slot formation to cooperate with a complemental stud-terminal provided on said integrity indicator means.

2. In an integrity indicator device for a cartridge fuse, the combination, with a cartridge fuse element and a support therefor having terminals by which said fuse may be included in the electrical circuit to be protected, of an integrity indicator element including an indicating means and means to support said indicating means fully exposed at or above the level of the cartridge fuse, in attention-arresting position and in electrical connection with said terminals, thereby to include said indicator means in a shunt with said fuse in the working circuit, said device being characterized by having said fuse cartridge element removable while said indicating means remains in place and further characterized by having a support for said indicating means supported by asupport having a bracket at one end of said cartridge fuse element and including binding screws and having a foot with an open slot by which said foot can be fitted to one of the binding screw terminals on said support, said bracket having a bracket part with a keyhole slot ,formation to cooperate with a complemental stud-terminal provided on said integrity indicator element and another bracket adapted to be held by a terminal screw at the other end of said fuse element, said last-named bracket having an eye and a slit to receive the bare end of a conductor leading from a terminal of said indicator means, whereby a shunt connection between said fuse terminals is completed, including said indicator means.

3. A supporting bracket-connector for a protective device of the class including a cartridge ruse element and an integrity indicator element, said bracket comprising a foot, an upright post and a bracket part formed with a pair of spaced apart keyhole slot connector means adapted to complement a pair of terminal studs upon said integrity indicator element, said bracket being further characterized by having said foot formed with an open slot to permit ready attachment with and detachment from, a binding screw constituting an electrical terminal for said elements in common.

4. A supporting bracket connector for a protective device of the class including a cartridge fuse element and an integrity indicator element, said bracket comprising a foot, an upright post and a bracket part formed with a pair of spaced apart keyhole slot connector means adapted to complement a pair of terminal studs upon said integrity indicator element, said bracket being further characterized by having said foot formed with an open slot to permit ready attachment with and detachment from, a binding screw constituting an electrical terminal for said elements in common and also by an orice in said bracket part to permit access of a tool to said binding screw.

LYMAN E. DODGE. 

